The invention relates to a device for connecting a first tube with a tubular element such as a connection tube or segment of such, wherein the tubular element extends with its end segment into an opening of the first tube and, by means of a tool, can be connected force-fittingly with it. The invention further relates to a method for connecting a first tube with a tubular element.
The invention also refers to a connection between a first tube and a junction element such as a valve, sprinkler head or further tube, comprising a hollow cylindrical connecting element, extending through an opening of the first tube with at least one segment into it and sealed relative to it, such as a housing which is connectable with the connecting element or the further tube.
According to DE 94 16 506 U1 a corresponding connection comprises a connection element with self-cutting threads which can be screwed into the opening of the first tube and which is encompassed by a hollow cylindrical housing which has a sealing effect relative to the connection element as well as also relative to the tube. A segment of the connection element extends within the first tube such that its free cross section is reduced in this region. In addition, several elements are required in order to establish the desired fluid-and pressure-tight connection.
It is also known to establish a connection by means of a sprinkler clamping collar such as are disclosed in EP 0 332 500 B1 or DE 94 11 013 U1.
According to DE 94 11 979 U1 a tube branch is realized by structuring a planar surface of a wall of a first tube from which extends a second tube.
A connection between a tube and a junction can, according to U.S. Pat. No. 2,015,246, be established by means of welding.
In U.S. Pat. No. 5,207,461 a device of the type cited in the introduction is disclosed which comprises a piston-cylinder arrangement as well as a frame with support receiving the first tube. Extending from the piston is a piston rod with which a bar is detachably connected, which comprises at the end a hemispherical segment whose maximum diameter is smaller than that of the opening of the first tube. The tube connection piece itself which is connected with the first tube, comprises a fish-mouth shaped end segment with flanged margin which changes over into a groove resulting in a material weakening which groove, in turn, is limited by an outer shoulder of the tube connection piece whose outer diameter is greater than that of the opening. For the force-fit connection of the tube connection piece with the first tube, the bar with the hemispherical head is introduced with the end at the fish-mouth side into the tube connection piece in order to be connected with the piston rod. The tube connection piece is subsequently placed onto the opening of the first tube. Tailored to the length of the tube connection piece, arms of the frame are braced on its outer margin in order to pull subsequently by means of the piston-cylinder arrangement the bar with the hemispherical head in the direction of the tube connection piece whereby the flanged edge extending within the first tube is bent over in the direction of the first tube in order to establish the force-fit connection. After sufficient deformation the hemispherical head with the bar can be pulled out of the tube connection piece. A flat sealing gasket ring extends between the shoulder and the outer surface of the first tube to effect a sealing between the tube connection piece and the first tube.
The present invention, for one, is based on the problem of further developing a device and a method of the type cited in the introduction such that with simple measures and independently of a piston-cylinder arrangement, a secure connection between a first tube and a tubular element, such as a second tube or other tubular junction elements, such as sprinkler head, can take place, and it is intended to ensure that the branching is fluid- and pressure-tight. For another, through the invention the problem is to be solved of further developing a connection of the type cited in the introduction such that with the least possible number of elements in a simple manner a fluid-and pressure-tight branching is possible without clamping collars or geometric changes of the connecting tube being required.
According to the device, the problem is solved thereby that the tool comprises at least two segments, axially displaceable one with respect to the other and extending within the tubular element up into the opening, that one of the segments comprises a radially projecting protrusion which engages behind the end segment of the tubular element when the segments are disposed within the tubular element, wherein the segments comprise external to the projecting protrusion a total effective diameter which is adjusted to the inner cross section of the tubular element.
The segment comprising the projecting protrusion is axially displaceable at least relative to a further segment such that the end segment extending within the first tube of the tubular element is bendable in the direction toward the inner wall of the first tube.
Due to the device according to the invention a force-fit connection of the tubular element with the opening of the first tube is possible with simple measures. For this purpose it is only required that the segment of the tool with a radially projecting protrusion is initially shifted from the outside through the tubular element into the interior of the first tube in order to displace subsequently the one or the further segments axially into the region of the opening wherein the total effective cross section of the segments extending within the opening corresponding approximately to the inner diameter of the tubular element. This ensures that when by means of the projecting protrusion of the first segment the margin segment, extending within the first tube, of the tubular element is bent in the direction toward the inner wall of the first tube, a lateral yielding of the segment cannot take place so that axial forces alone must act onto the segment effecting the bending or flanging.
It is simultaneously ensured that the tubular element is not exposed to uncontrolled forces which can lead to impermissible deformation.
The invention provides, in particular, that the tool comprises two segments, axially extending within the opening of the first tube and rotatable within the opening, that the first segment having the projecting protrusion comprises a cylinder-form basic body and the second segment has a sickle-form in cross section whose concave surface in the contact region with the first segment is adapted to its outer geometry.
In other words, the first and second segments which are axially displaceable one relative to the other, have a total cross section which corresponds approximately to a circle form, whereby is possible the good adaptation to the inner cross section of the tubular element to be connected with the first tube.
The projecting protrusion itself comprises preferably a cylinder form with an underside extending obliquely in the direction of the basic body, with the angle of inclination laid out such that the surface contact of the end segment to be bent over of the tubular element on the inner wall of the first tube becomes possible.
The protrusion should further extend flush from that region of the outer surface which is displaceable along the second segment.
The bending over or flanging of the end segment extending within the first tube takes place peripherally thereby that the tool is rotatable successively about its longitudinal axis.
According to the method, the problem for the force-fit connection of the tubular element with the opening of the first tube is solved thereby that the tubular element is introduced with its end segment into the opening of the first tube, that through the tubular element a first segment of the tool with a radially projecting protrusion is introduced into the interior of the first tube such that the protrusion extends between the external free edge of the tubular element and the inner wall opposite the opening of the first tube, that axially along the first segment a second segment is shifted up into the opening region of the first tube wherein the first and the second segment in the region of the opening has a total effective cross section adapted to the inner cross section of the tubular element, that the first segment is shifted in the direction of the opening along the second segment while simultaneously the margin segment of the tubular element extending within the first tube is bent, that the first segment subsequently is shifted in the direction of the tube interior and rotated about its longitudinal axis in order to bend over subsequently, in a previously described manner, further regions of the end segment of the tubular element and, consequently, to connect them force-fittingly with the margin of the opening of the first tube.
After the end segment of the tubular element has been bent or flanged to the required extent, first, the second segment and subsequently the first segment are removed from the tubular element.
The pressure-and fluid-tight connection between the tubular element and the first tube takes place thereby that the tubular element on the outside of the tube comprises a preferably encircling reception for a sealing element such as an O-ring.
A connection of the type described in the introduction is distinguished thereby that the segment, or segments, extending on the inside along the first tube are pressed over, flanged or compressed. In particular, it is provided that the connection element having a hollow cylinder form comprises on the outside of the tube a reception, preferably encircling, for a sealing element, such as an O-ring.
A connection between a first tube and a junction element, such as a valve, sprinkler head or a further tube, comprising a hollow cylindrical connection element connectable with the junction element or the further tube, such as a housing, which is sealed relative to the first tube and extends with a segment within an opening of the first tube, is also distinguished thereby that the segment of the connection element is connected with the first tube through welding processes, with the hollow cylindrical segment of the connection element, adapted at the circumferential side of the opening of the first tube comprises protrusions forming dot-form contact sites which are welded to the first tube, in particular with the margin encompassing the opening and/or the hollow cylindrical segment of the connection element comprises a recess, adapted to the cross sectional geometry of the tube, which is welded to the margin-side region of the opening.
Due to the teaching according to the invention it is only required to place the connection element, such as a housing, with its segment into the opening of the first tube and subsequently, by applying electrodes, to weld the segment to the first tube and specifically in particular with the margin region of the opening so that the required force fit between the connection elements, such as a housing, and the first tube is ensured.
The recess of the hollow cylindrical segment is preferably such as to be encircling and comprises an annular step, adapted to the outer geometry of the tube, which can be welded to the first tube, preferably to the inner margin of the opening.
The teaching according to the invention opens the possibility of establishing with simple measures a fluid-and pressure-tight connection between the connection element, such as a housing, which is connectable with the junction element or a further tube, and the first tube, withxe2x80x94in contrast to previously known prior artxe2x80x94the cross section of the first tube in the region of the connection element not needing to be decreased. Rather, the possibility exists that the segment extends at the front wall flush or nearly flush with the opening-side inner walls of the first tube and runs offset toward the inside.
In order to permit the simple placement of the connection element into the opening of the first tube and/or to make available simultaneously a contact surface conducting the welding current to the required extent between the connection element and the first tube, the opening can be chamfered at the outside wall at least in regions, with the recess of the segment, extending into the opening, of the connection element having a congruent geometry.
The connection element itself having a hollow cylindrical form should comprise on the outside of the tube a reception, preferably encircling, for a sealing element-such as an O-ring-in order to ensure the required sealing between the elements.